Problems whit PH?

[Simonsen]

Hi!

For two weeks ago i notice that some of my new colonies got STN from the base and up. I have been readed for a while ago that When a coral got STN this could be a KH/PH problem. In that case i was looking for my Apex PH module that the PH was under 7,50. In the lowest its on 7.39.
First question is; How can i raise this safely whitout killing my whole collection of SPS?

My KH was measured to 5.6ppm If my measuring kit is right.

I use Aquaforest Probiotic Reef salt at this moment but iam changing to RedSea Coral Pro today.

How many gallons is it safe to change to raise the KH/PH slowly?

Here is a picture of my swings monitored by my Apex Computer.

Thanks for Answer!

 

[Randy Holmes-Farley Verified Community Expert]

I'm not convinced pH 7.39 is real. I'd recalibrate and check again.

This has more:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/

 

[Simonsen]

I'm not convinced pH 7.39 is real. I'd recalibrate and check again.

This has more:

pH And The Reef Aquarium
http://www.reefedition.com/ph-and-the-reef-aquarium/

Yeah. Gonna calibrate first, but got a little worried of the KH drop and a couple of SPS startet to loose flesh on the base.

Gonna read the link you give me! Thanks for reply.

 

[Randy Holmes-Farley Verified Community Expert]

If it is 5.6 dKH, it definitely needs boosting, and that will also bring up pH a bit.

 

[Reef 450]